It’s an honest question but let me rephrase it slightly. Have you eaten your green leafy vegetables today? If this is the case you have probably also been feeding your gut bacteria with sulfoquinovose, or let’s call it SULQ here for simplicity. Nothing to sulk about, it’s a really good thing according to brand new findings. SULQ is hidden in the leaves of green vegetables such as spinach and kale and is devoured by your good gut bacteria, which use it as a source of energy to fuel their growth. And the greener the plant the more SULQ they produce.
Researchers have now identified a previously unknown enzyme called YihQ used by bacteria, fungi and other organisms to feed on the unusual but abundant sugar sulfoquinovose. The finding suggests that leafy greens are essential for growing good gut bacteria, and thus denying any space for bad bacteria to colonise the gut. In a critical discovery about how bacteria feed on SULQ, an explanation was found to how the good bacteria protect our gut and promote health. Every time we eat leafy green vegetables we consume significant amounts of SULQ sugars, which are used as an energy source by the good gut bacteria. These beneficial bugs provide a protective barrier that prevents growth and colonisation by bad bacteria.
SULQ has also been shown in other in vitro studies to have anticancer properties, an added benefit.
But there is more
As a sulfur-containing sugar, SULQ is produced by photosynthetic organisms like plants at an enormous rate of 10,000,000,000 tons (that is 10 gigaton) per annum and is degraded by bacteria as a source of carbon and sulfur. Sulfur is critical for building proteins, the essential components of all living organisms. SULQ is the only sugar molecule which contains sulfur, and digestion of the molecule by bacteria releases sulfur into the environment, where it re-enters the global sulfur cycle to be reused by other organisms.
This work answers a 50-year mystery that has surrounded how sulfur – an element essential for life on Earth – is used and recycled by living organisms.
If you want to make your intestinal bugs even happier, other foods that also fuel the growth of beneficial bacteria include kefir, artichokes, asparagus, bananas, chicory, dandelion root, garlic, jicama, leeks, onions, barley, rye and wheat. Your choice.